681534 has 40 divisors (see below), whose sum is σ = 1748208. Its totient is φ = 194400.

The previous prime is 681523. The next prime is 681539. The reversal of 681534 is 435186.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 681498 and 681507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 834 + ... + 1434.

2⁶⁸¹⁵³⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681534, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (874104).

681534 is an abundant number, since it is smaller than the sum of its proper divisors (1066674).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

681534 is a wasteful number, since it uses less digits than its factorization.

681534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622 (or 613 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 681534 is about 825.5507252737. The cubic root of 681534 is about 88.0026686519.

The spelling of 681534 in words is "six hundred eighty-one thousand, five hundred thirty-four".